Vitamin C elevates red blood cell glutathione in healthy adults

Pre-transplant nephrectomy was done in a 25-year-old man for calculous pyelonephritis using a retroperitoneal laparoscopic approach with a newly devised ligature applicator-dissector- kidney retractor.     

An extended panel of hamster-human hybrids for chromosome 2q

A hamster-human hybrid containing only the q arm of chromosome 2 has been used to construct a panel of hybrids bearing reduced regions of chromosome 2 using the technique of irradiation fusion gene transfer. The human chromosome 2 carried the Ecogpt gene and all hybrids were selected using this marker. The integrated Ecogpt gene was localized to the region 2q33-34, resulting in the selective retention of this region in the hybrids. These data were combined with another previously constructed panel of hybrids containing regions of 2q, which were enriched for the region 2q36-37. The combined hybrid panel is useful for the mapping of new markers to defined regions of chromosome 2 and for the cloning of genes located on 2q by a positional strategy.     

Organ preservation in anal and rectal cancers

For the past 10 to 15 years, radiation therapy and chemotherapy have played an increasingly important role in the treatment of various gastrointestinal malignancies, most prominently in anal and rectal cancer. Critical issues in the care of patients with anal and rectal cancer include not only local control and survival but organ preservation as well. For patients with carcinoma of the anal canal, external-beam irradiation with 5-fluorouracil and chemotherapy with mitomycin C have replaced surgery as primary therapy. Current studies are optimizing this therapy. In contrast, the management of distal rectal cancer is in evolution. Although the abdominoperineal resection has been long regarded as the definitive treatment of distal rectal cancer, it is associated with substantial morbidity (loss of anorectal function with a permanent colostomy and a high incidence of sexual and genitourinary dysfunction). As an alternative, treatment programs utilizing sphincter-preserving procedures with radiation therapy and chemotherapy are under active investigation. In selected patients, these strategies appear promising, and there have been reports of satisfactory local control and survival, as well as preservation of sphincter integrity.     

A predictive model for matrix and analyte effects in electrospray ionization of singly-charged ionic analytes

In electrospray ionization (ESI), droplets with a surface excess charge are created. The rate of production of surface excess charge is a constant and is equal to the rate of ion production. The ions appearing in the mass spectrum are postulated to be those that formed the surface excess charge at the time of droplet formation (or their collision products). An equilibrium model based on competition among the ions in the solution for the limited number of excess charge sites has been developed. This model accurately predicts the response curves of singly-charged ionic analytes as a function of the concentration of electrolyte and other analytes and provides an explanation for the selective effectiveness of ESI. At low concentrations of total analyte (micromolar and less), the response curves are linear, indifferent to the presence of other low concentration analytes, and suppressed by electrolyte concentrations in excess of the minimum required. At higher analyte concentrations, the response becomes independent of analyte concentration but highly affected by the presence of other analytes.     

Response of Plasmodium falciparum to chloroquine and Fansidar in vivo and chloroquine and amodiaquine in vitro in Uganda

The response of P. falciparum to chloroquine and pyrimethamine-sulfadoxine in vivo and chloroquine and amodiaquine in vitro was investigated in parasitaemic school children from six locations. Mean parasite sensitivity to chloroquine at day 7 was 74% (range 61-97) with parasite clearance rates between 2-3 days and complete defervescence in 85% of febrile children. Sensitivity declined in the four sites followed up to day 14 to 45% (range 37-53). Parasites were significantly more sensitive to pyrimethamine/sulfadoxine at 5/6 sites (100% day 7) but 5% of subjects became parasitaemic by day 14. In vitro isolates were significantly less sensitive to chloroquine than to amodiaquine with a mean 99% effective concentration of 348 mumol/L compared to 6.44 mumol/L. Clearly the role of chloroquine as the primary therapy for uncomplicated P. falciparum malaria should be reconsidered especially in the light of increasing disease severity and resurgence. Amodiaquine may be suitable alternative with pyrimethamine/sulfadoxine as second line and for more severe malaria prior to referral. The cost of alternative antimalarials and the dynamic and deteriorating pattern of resistance are powerful arguments for more objective slide diagnosis to minimise drug pressure and a regular drug sensitivity surveillance system. We believe that the latter should concentrate on measuring clinical drug efficacy in symptomatic outpatients rather than in asymptomatic children while the former needs more pragmatic and economical strategies possibly centred on seasonality and risk.     

Fatigue of Kaowool reinforced aluminum: Effect of shot particle wall thickness

The fatigue performance of Kaowool fiber reinforced 339 aluminum composites at 300°C is limited by spherical thin walled hollow Kaowool shot particles. These act as crack initiation sites particularly when located at the surface. This problem does not occur for thick walled particles or particles filled with the aluminum matrix. The effect of wall thickness (t) is evaluated from finite element analysis of both 2D and 3D models, with and without plasticity. Both models predict that hollow thin walled particles act as defects, while thick walled particles act as reinforcements, this transition being defined by a critical wall thickness (t _c). The 3D model is preferred in that it predicts more accurate and smaller values of t _c. Specifically, the 3D elastic/plastic model predicts that the largest stress concentration occurs for a fractional surface particle and that in this condition t _c = 0.18a, where a is the particle radius. This value agrees with our experimental observation that particles with t > 0.2a do not initiate failures.     

A methodology for assessing gamebird use of short rotation coppice

Gamebirds provide a considerable incentive to plant and manage new woodlands. The supplementary income thus generated can improve their overall value. Other studies suggest that Short Rotation Coppice (SRC) crops may provide an attractive habitat for some gamebird species and could increase the value of the crop. To investigate this, the use by pheasants and partridge of different types of SRC at one site was assessed.

A method using sand quadrats to record gamebird footprints and hence relative use was developed. Pheasant footprints were recorded more frequently in the quadrats alongside the willow coppice, whereas partridge footprints occurred more frequently alongside the poplar coppice. Footprint analysis offers a reliable method of investigating how gamebirds use different types of SRC within small areas. The results are considered in terms of the placement of short rotation coppice plantations in the landscape to improve their ecological design.     

Early American neurologic textbooks

Although European treatises were translated and available to American doctors interested in neurology during the 19th century, the early American neurologic textbooks were distinctive in their comprehensive integration of basic and clinical science. William A. Hammond, in 1871, published the first comprehensive American textbook of neurology, preceding the manuals by Gowers (1886) and Oppenheim (1894) by more than a decade. Four other American adult neurologic textbooks expanded on Hammond's model and incorporated other important topics, including neurologic anatomy, the formal examination, neurochemistry, and complete bibliographies. Bernard Sachs' 1895 textbook was the first pediatric neurologic textbook published in America and made significant contributions to the organization of childhood neurologic disorders. These works functioned as centralized resources for neurologic information, were influential educational tools, and helped foster a growing appreciation of the American neurologic school both nationally and internationally.